<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/95689>95689</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [Flang] fatal internal error: CHECK(tokens.SizeInTokens() == 1) failed at /root/llvm-project/flang/lib/Parser/prescan.cpp(190)
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            flang
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          k-arrows
      </td>
    </tr>
</table>

<pre>
    Reproducible on Godbolt:
https://godbolt.org/z/bexnKds9n

Reproducer:
```f90
integer :: i

i = 0

pr&
&i&
&nt *, i

end
```

Stack dump:
```console
fatal internal error: CHECK(tokens.SizeInTokens() == 1) failed at /root/llvm-project/flang/lib/Parser/prescan.cpp(190)
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.      Program arguments: /opt/compiler-explorer/clang-llvmflang-trunk-20240616/bin/flang-new -fc1 -triple x86_64-unknown-linux-gnu -S -mrelocation-model pic -pic-level 2 -pic-is-pie -target-cpu x86-64 -mllvm -x86-asm-syntax=intel -resource-dir /opt/compiler-explorer/clang-llvmflang-trunk-20240616/bin/.. -mframe-pointer=all -o /app/output.s -x f95-cpp-input /app/example.f90
 #0 0x00000000038654d8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-llvmflang-trunk-20240616/bin/flang-new+0x38654d8)
 #1 0x0000000003862e4c SignalHandler(int) Signals.cpp:0:0
 #2 0x00007a1a6b442520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #3 0x00007a1a6b4969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #4 0x00007a1a6b442476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #5 0x00007a1a6b4287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #6 0x0000000004e72a29 (/opt/compiler-explorer/clang-llvmflang-trunk-20240616/bin/flang-new+0x4e72a29)
 #7 0x0000000004ac4c72 Fortran::parser::Prescanner::Statement() (/opt/compiler-explorer/clang-llvmflang-trunk-20240616/bin/flang-new+0x4ac4c72)
 #8 0x0000000004ac4d28 Fortran::parser::Prescanner::Prescan(Fortran::common::Interval<Fortran::parser::Provenance>) (/opt/compiler-explorer/clang-llvmflang-trunk-20240616/bin/flang-new+0x4ac4d28)
 #9 0x0000000004aac555 Fortran::parser::Parsing::Prescan(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>> const&, Fortran::parser::Options) (/opt/compiler-explorer/clang-llvmflang-trunk-20240616/bin/flang-new+0x4aac555)
#10 0x00000000038b7cb3 Fortran::frontend::FrontendAction::runPrescan() (/opt/compiler-explorer/clang-llvmflang-trunk-20240616/bin/flang-new+0x38b7cb3)
#11 0x0000000003be4bd0 Fortran::frontend::CodeGenAction::beginSourceFileAction() (/opt/compiler-explorer/clang-llvmflang-trunk-20240616/bin/flang-new+0x3be4bd0)
#12 0x00000000038b6285 Fortran::frontend::FrontendAction::beginSourceFile(Fortran::frontend::CompilerInstance&, Fortran::frontend::FrontendInputFile const&) (/opt/compiler-explorer/clang-llvmflang-trunk-20240616/bin/flang-new+0x38b6285)
#13 0x00000000038a5be7 Fortran::frontend::CompilerInstance::executeAction(Fortran::frontend::FrontendAction&) (/opt/compiler-explorer/clang-llvmflang-trunk-20240616/bin/flang-new+0x38a5be7)
#14 0x00000000038bc2cd Fortran::frontend::executeCompilerInvocation(Fortran::frontend::CompilerInstance*) (/opt/compiler-explorer/clang-llvmflang-trunk-20240616/bin/flang-new+0x38bc2cd)
#15 0x0000000001fee0a8 fc1_main(llvm::ArrayRef<char const*>, char const*) (/opt/compiler-explorer/clang-llvmflang-trunk-20240616/bin/flang-new+0x1fee0a8)
#16 0x0000000001ed6fe4 main (/opt/compiler-explorer/clang-llvmflang-trunk-20240616/bin/flang-new+0x1ed6fe4)
#17 0x00007a1a6b429d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#18 0x00007a1a6b429e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#19 0x0000000001fed00e _start (/opt/compiler-explorer/clang-llvmflang-trunk-20240616/bin/flang-new+0x1fed00e)
flang-new: error: unable to execute command: Aborted (core dumped)
flang-new: error: flang frontend command failed due to signal (use -v to see invocation)
flang-new version 19.0.0git (https://github.com/llvm/llvm-project.git 85a7bba7d28365ff98dae74f20ebf9f53d42023a)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/compiler-explorer/clang-llvmflang-trunk-20240616/bin
```

The following is the original reproducer:
https://github.com/lfortran/lfortran/blob/main/integration_tests/line_continuation_02.f90
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzMWFtv2zgW_jXyCyGBoi6WHvzgSeKZYhbYYtJ3gyKPZG4oUiCpxJ1fvyAlX-S22WZRA1O0hXk75_vOTeSh1opOAWyi4reoeFzR0R202bzE1Bj9ZleN5l83f8FgNB-ZaCQgrdDvmjdauijbRvgxwtuDc4P1I7KLyK6bVhNtuojs_o7IroGj-pPbWk3bp_9PQsGc5UQlnv62NZ5mhHLQgUF-S7ZF4lqAQFH2iPD11GAiUs4TpBTXA-VQRLYReVgKAcVvdF-vPjvKXhAf--FbjEwrqyVMsy11VCKP1igqERijPS308MfTw58RqZx-AWWTZ_E3fFJfwiAiVURqz8HTSP3vlgoJHFEPdWe0dhHZSfnax4PR_wHmh62kyptViiYiu8_UWDAR2Q0GLKMqYcMQkSqtcUTqCdnnfz1tn5-QHZteOERRM3bIwKCNQ06jG88JdxibhOl-VvytfmHtCDYiO0QVR0IxOXJA7gCIGWoPqKHsxRnKIPmhBXES4fqz0Z2hPaKmG3tQzoPwrPXgtTDdD0KCieE4SG0CReaZxx5OsEHszKheYoJJjsu09FEm1MlAsYI3FLcsRbEzYpCAjlW5L_N4VC9Kv6lYCjUe406NKH5GcW9Aakad0CruNQeJBsFQPAgWS3gFicg0EDYeBKDYUdOBi9kwerlxmaO498BQ7IfU9rH9qhw9RtmjDwmJYgNWj4ZBzIX5JTSTBMV9a2gP8aBD3EXZI5USxdrLpz4Odnp0w-gSi-IjausiZsMQCzWM7rIFjrQfJCTnjEMRyTDCR3z6k1VlkfMKhXgIaWi_2unHZyOUCx7-4l0ekeqyydC3vbbOAO19Gvq8Uy4EvI_7X-jniPyGjzPIc9R7FukNCwI5Q8-iU1T-QRWXXls1g5qmbcifbIvDv7MgMgta05SWTZ6TguCZxpSGc3Cdg2paYInVSRnghSMLcNlSZl3WLUODOxigfP8ipPyYgnB-oSC_BZ2vS9TZwPOj4PN1uZBdLGWTat1miDa-pnxIcji4kFxe-yyHNaH3iphZ-EL7eqGdspytCdpp4wxVU1QPU8Gdoz_UXHUaPzvqwNeyU2W_C-wJ1QJ2dQubk-rnYc_jiFSLI0z3vZ5_f_L15ZXKKHt4R6x-BUUVgyh7uit9TpZ5Xi_pU1YUxTv0qbFCdbfcrePT1H7Pjsc0nQYNtYLtrTPhxAM7UOMr2Xmzn9g7Q4X_fk3LnvzVDirDl8XfBs7r2RPylwc318UfQv334L9I9o7GDLY6G9PXzJvS36xZky0RtkYr569NYbSbR1vmsc6lf1QXw96x5AdwC_TLkt9A3nD8HvoHzeF3UNfgG-iEeg4f652QMC_dk8cEc8GD3HihJFXxUS_cELnN71tDTGw-KetCDn8nNL-v8pO_T3gFVzF9P497QywslS0tRYsG1u97_IZomIUjsNFdnP3zpr4r3cBmQTe_CQxGGH-P7kzswvp1vud-NBy29_SqZ7GgWVzTTFsATCvUsnTfUy_h6pq5NYZ-_QvaubyegnA71-Hl3L0ozAgXFBY3mRR42UKOPPw7QZg0LCCsb65pNa8_eG8NRxYyq1uZkGO03_tje-uocfsrjj-tBfKllvrG_xxjQJP8u3nQ6ziDuKxm28trflS0keDfzXNeIX9LoiFr0Nbff4F7fEwbCG9e4P9DYphFp-Q7iTs1AvgYlF0u7aMFFL-GOQAkrrL5Vgt6BWOFViitE5zgTgTDfey5n_hTVUHXTUPXnFRZWbRtXXEK67wlGJq2bouM5wSTjJ4hfAmPY0_uR2_ueV9466Dw3va7B23FcVoKZUdK4I_C_Jq-wI9bPF8OgFotpX4TqkPChl6GNqIT3ubm2ybVezZs55K6-NlI7dNgKl270NEywWt7B9bZkA4K9kwrJ9Q4rWDiX-Qrvsl4ndV0BZt0nVYFyWuSrg6bbF2ULcsbCrwFIDxlZZ02mKRQlbzO1yuxORkAV5jgNGGcZrggwDluOeRNlGPoqZCJN1yiTbcKnZ1NXZRVvZK0AWlDT5CQueVEouJxZTYhQJqxs1GOpbDOXiQ44WRoJO7CieIR_RPbYqvRyM3_3_eaDPS6If8NAAD__6Cnhfo">